Process for clarifying aqueous systems employing quaternary ammonium adducts of polymerizable tertiary ammonium salts and acrylamide

ABSTRACT

This invention relates to adducts of salts of polymerizable tertiary amines with acrylic compounds illustrated by acrylamide and acrylonitrile; to polymers and copolymers containing said adducts and to processes for preparing them. This invention also relates to the use of said polymers and copolymers, particularly in the clarification of turbid waters by flocculation or flotation of oil and/or suspended solids. In the preferred embodiment, the quaternary adduct monomer is: ##STR1## where X is an anion, preferably halide such as chloride or carboxylate such as acetate; and polymers and copolymers containing units thereof.

This is a division of application Ser. No. 523,813, filed Nov. 24, 1974.

When a mixture of two acrylic monomers is polymerized, a copolymercontaining the respective monomer units is formed. Thus a mixture ofacrylamide and acrylic acid will yield a random copolymer which can berepresented as follows: ##STR2##

When acrylamide (AM) is copolymerized with the acetate salt ofdimethylaminoethyl methacrylate (DMAEMA-acetate) one expects thefollowing copolymer to form: ##STR3##

We have now discovered that actual formation of this copolymer requiresspecific reaction conditions and that generally when acrylamide iscopolymerized with DMAEMA acetate the following terpolymer is formed:##STR4##

We have now discovered that this terpolymer is formed due to thegeneration of quaternary ammonium adduct groups from tertiary ammoniumsalt groups and acrylamide: ##STR5## where S represents either themonomer or copolymer residue. This adduct formation can take placebefore, during and after the copolymerization reaction.

The present invention relates to adducts formed before or during thecopolymerization reaction.

The adducts described herein are quaternary ammonium salts, variouslyreferred to as such, as adducts, as quaternary adducts, as quaternaryammonium adducts, or simply as quats.

The principal method of the present invention involves reaction of aconjugate acid salt of a tertiary amine with acrylamide according to thefollowing equation: ##STR6##

Two of the R, R', and R" groups are substituted groups, preferably alkyland most preferably methyl groups to minimize steric hindrance aroundthe nitrogen atom and thus maximize reaction rate. The third group maybe an hydroxyethyl or a methacryloxy-ethyl group. The acid used to formthe conjugate acid of the tertiary amine may be an aliphatic carboxylicacid such as acetic acid or a mineral acid such as hydrochloric acid.

Reaction of a tertiary ammonium salt with acrylamide may be conducted ineither an aqueous or nonaqueous solvent. Nonaqueous solvents areadvantageous for isolation of the quaternary ammonium salt. In2-propanol, for example, crystallization of the quaternary ammonium saltshifts the equilibrium in the desired direction. The crystallizedproduct, in most cases, requires no further purification.

Reactions in nonaqueous solvents are preferably conducted withhalf-neutralized amines at temperatures of 0°-25°. To maximize reactionrate, total reactant concentration should be as high as possible withoutexceeding the solubility of the least soluble component. The ratio oftotal amine molar concentration to acrylamide concentration ispreferably between 1/10 and 4/1.

For most purposes, isolation of the quaternary ammonium salt isunnecessary and in these cases, the reaction is preferably conducted inaqueous solution at a temperature of from 0° to 100° at atmosphericpressure and at a pH of from 5 to 9. Reaction rate increases withincreasing temperature and with increasing pH. The equilibrium constantfor formation of the quaternary ammonium salt, however, decreases withincreasing temperature and is independent of pH within the specifiedrange. Preferred temperature and pH range for formation of thequaternary ammonium salt are 25°-50° and pH 6-8, respectively.

At fixed temperature and pH, the equilibrium concentration of quaternaryammonium salt may be increased by increasing the total reactantconcentration and/or by increasing the acrylamide to amine concentrationratio. For example, at an initial total amine concentration of 1mole/liter and 1/1 molar ratio of acrylamide to amine, less than 50% ofthe amine is converted to a quaternary ammonium salt at 55° and pH-7.0.But, at the same temperature and pH, equilibrium conversion in excess of90% can be achieved by employing an initial amine concentration of 3mole/liter and a 3/1 molar ratio of acrylamide to amine. At any reactantconcentration and at any ratio of acrylamide to amine, quaternaryammonium content at equilibrium is governed by the relationship,##EQU1## where Qe=the equilibrium concentration of quaternary ammoniumsalt, R₃ N₀ =the initial concentration of tertiary amine, n=the ratio ofinitial acrylamide concentration to initial amine concentration, andK=the equilibrium constant for formation of the quaternary ammoniumsalt. Values of K for conversion of N,N-dimethyl-N-(2-hydroxyethyl)ammonium chloride to its quaternary ammonium chloride, useful forapproximating extent of conversion of similar tertiary amines to theirquaternary ammonium salts, are found to be 3.2 M⁻¹ at 25°, 2.0 M⁻¹ at55°, and 0.7 M⁻¹ at 85°. These equilibrium constants are invariant overa pH range of 5.8 to 7.8.

In the case of hydrolyzable amines such as acrylic or methacrylic acidesters of alkanolamines, care must be exercised to minimize the extentof hydrolysis during the quaternization reaction. Rates of hydrolysis,like rates of quaternization, are increased by increasing temperature aswell as by increasing pH. Rates of quaternization may be maximized withrespect to rates of hydrolysis, however, by applying the principlesoutlined above; i.e., by employing high reactant concentrations and highratios of acrylamide to amine. Thus, for hydrolyzable amines, totalreactant concentrations of about 30-50% by weight and molar ratios ofacrylamide to amine in excess of about 2/1 are preferred.

In the case of polymerizable amines, the amine may be converted withacrylamide to its quaternary ammonium salt prior to polymerization. Theisolated material undergoes homopolymerization or copolymerization withacrylamide when excess acrylamide is added to the monomer mixture.Alternatively, the quaternary ammonium salt of a polymerizable tertiaryamine may be prepared in situ. A free radical initiator may be added tothe reaction mixture at the beginning of the quaternization reaction orafter a time interval sufficient to ensure equilibration prior topolymerization. In either case, the quaternary ammonium salt undergoesvinyl copolymerization with its constituent parts, with excessacrylamide, and with hydrolysis products, if present, to form cationicpolyelectrolytes. By applying the principles outlined above, copolymerscontaining from <1 to >99% quaternary ammonium groups (based on totalamine) can be prepared. For example, polymerization of a mixture ofacrylamide (2 equivalents) and dimethylaminoethyl methacrylate (1equivalent) at a concentration of 50% by weight in an aqueous solution(pH=7.0) at 85° produces a copolymer with <5% quaternary ammonium saltcontent. However, polymerization of the same monomer mixture at 55°produces a copolymer with 50-60% quaternary ammonium salt contentprovided that reaction is discontinued after about 6 hrs.

The methods described herein are applicable as well to the preparationof polymeric quaternary ammonium salts from polymeric tertiary amines.For example, homopolymers of dimethylaminoethyl methacrylate areconverted, in part, to polyquats by treatment with acrylamide in aqueoussolution at pH-7.8 and 60°. Since polymers of hydrolyzable tertiaryamine monomers are more stable toward hydrolysis than the respectivemonomers, elevated temperatures (60°-100°) and elevated pH values (7-9)may be employed and, in fact, are preferred for quaternization ofpreformed polymers.

The polymers described herein may be prepared by any method, such as bysolution or emulsion polymerization. The polymeric products describedherein are widely useful as fluocculants and flotation aids. The methoddescribed herein for producing these materials is particularlyadvantageous in that the quaternary ammonium salt content can bedeliberately varied to meet the demands of diverse uses.

To assist those skilled in the art to practice this invention, thefollowing examples are given. Concentrations are expressed inmoles/liter (M) or in percent by weight. Temperature is expressed °C.Abbreviations of chemical compounds are as follows: AM=acrylamide;DMAE=N,N-dimethylethanolamine; DMAEMA=N,N-dimethylaminoethylmethacrylate; AN=acrylonitrile.

EXAMPLES (1) Preparation of the DMAE-AM quaternary ammonium chloride.

36 parts of AM 89 parts of DMAE, and 126 parts of DMAE.HCl (1:1:2 molarratio of AM:DMAE:DMAE.HCl) are dissolved in 500 parts of warm (40°-50°)2-propanol. The solution is immediately cooled to 25° whereuponcrystallization of the product begins within 10 min. After 16 hrs., thecrystals are collected by filtration and dried in vacuo to give 98 parts(100% yield) of directly pure DMAE-AM quaternary ammonium chloridehaving mp=157°-158°.

(2) Preparation of the DMAE-AN quaternary ammonium chloride.

As in example (1), 16 parts of AN, 55 parts of DMAE, and 78 parts ofDMAE.HCl are dissolved in 450 parts of warm (40°-50°) 2-propanol. Thesolution is cooled to 25° then, after 48 hrs., filtered to give 32 parts(57%) of directly pure DMAE-AN quaternary ammonium chloride, mp=110°.

(3) Preparation of the DMAEMA-AM quaternary ammonium chloride.

71 parts of AM, 79 parts of DMAEMA, 97 parts of DMAEMA.HCl, and 2 partsof phenothiazine are dissolved in 130 parts of 2-propanol by warming to40°. The solution is cooled to 0° then, after 1 week, filtered to give36 parts of DMAEMA-AM quaternary ammonium chloride as a crystallinesolid. Concentration of the mother liquor to 50% of its initial weight,followed by cooling to 0° yields an additional 30 parts of quaternaryammonium chloride, raising the total isolated yield to 50%.

(4) Equilibration of the DMAE-AM quaternary ammonium chloride with itsconstituent parts.

A sample of a 2.54 M solution of the DMAE-AM quaternary ammoniumchloride (prepared as described in example (1) in a pH-7.8 phosphatebuffer is placed in an nmr sample tube. An nmr (nuclear magneticresonance) spectrum is recorded within 10 min. of sample preparation.The nmr sample tube is then immersed in a constant temperature baththermostatted at 55° and removed periodically for further nmr analysis.As equilibrium is approached, the singlet resonance of the N-methylgroups of DMAE.HCl (δ2.95) increases in area at the expense of thesinglet resonance of the N-methyl groups of DMAE-AM quaternary ammoniumchloride (δ3.23). Equilibrium is achieved within 6 hrs. at 55° (nofurther changes in the nmr spectrum occur thereafter) to produce amixture containing 64.8% DMAE-AM quaternary ammonium chloride and 35.2%DMAE.HCl. Thus, the equilibrium concentrations of DMAE.HCl, and AM are1.64 M, 0.90 M, and 0.90 M, respectively, and the equilibrium constantfor formation of the quaternary ammonium salt, K, is 2.0 M⁻¹.

In like manner, the equilibrium constant for conversion of mixtures ofDMAE.HCl and AM to DMAE-AM quaternary ammonium chloride has beenevaluated as a function of total amine concentration at each of 3 pHvalues. The results are summarized in Table I.

                                      TABLE I                                     __________________________________________________________________________         Total Amine                                                                            Time Required for                                                                       % Total Amine Quater-                                                                            Average                            pH(25°)                                                                     Concentration, M                                                                       Equilibration, hr.                                                                      nized at Equilibrium                                                                      K,M.sup.-1 (55°)                                                              K,M.sup.-1 (55°)            __________________________________________________________________________    5.8  2.54     168       62.8        1.80                                      5.8  1.52     168       55.9        1.89   1.8 ± 0.1                       5.8  0.51     168       37.2        1.85                                      7.0  2.54     24        64.7        2.02                                      7.0  1.27     24        51.2        1.71                                      7.0  0.76     24        41.9        1.60   1.7 ± 0.2                       7.0  0.25     24        24.2        1.67                                      7.8  2.54     6         64.8        2.02                                      7.8  1.52     6         55.7        1.89   1.9 ± 0.1                       7.8  0.51     6         37.7        1.92                                      __________________________________________________________________________

(5) Temperature dependence of the equilibrium constant for formation ofthe DMAE-AM quaternary ammonium chloride

The equilibrium constant for formation of DMAE-AM quaternary ammoniumchloride from mixtures of DMAE.HCl and AM has been evaluated at 85° andat 25° by the method described in example 4. All measurements wereconducted in a phosphate buffer having pH=7.8. At 85°, equlibrium(approached from the quaternary ammonium salt) is achieved within 2 hrs.and is governed by the relationship: K=0.7 M⁻¹. At 25°, equilibriumrequires 1 week and equilibrium is governed by the relationship: K=3.2M⁻¹.

(6) Solution polymerization of DMAEMA-AM quaternary ammonium chloride.

25 parts of DMAEMA-AM quaternary ammonium chloride (prepared asdescribed in example 3) is dissolved in 225 parts of deionized water at25°. The solution, having pH=6.0, is treated with 0.5 parts of4,4'-azobis (4-cyanovaleric acid), degassed, then warmed to 50° undernitrogen whereupon polymerization occurs as indicated by a gradualincrease in viscosity. After 30 min., an additional 0.5 parts ofinitiator is added and temperature is maintained at 50° for 1 hr.thereafter. Nmr analysis of the product solution shows >90% conversionof monomer to polymer and >95% retention of quaternary ammonium groupsin the polymeric product.

(7) Reactions of poly(DMAEMA-AM quaternary ammonium chloride).

Aqueous solutions of poly (DMAEMA-AM quaternary ammonium chloride)buffered at pH=7.8 and at pH=5.8 are prepared by mixing equal parts ofthe polymer solution of (example 6) and the appropriate phosphatebuffer. Upon incubation at 58°, the buffered solutions are observed toundergo the changes summarized in Table II. The changes are not governedby an equilibrium relationship since AM produced by retroquaternizationof the polymer is consumed by polymerization.

                  TABLE II                                                        ______________________________________                                                 % Quaternary Ammonium Salt Remaining                                 Time at 58°                                                                       pH = 7.8            pH = 5.8                                       ______________________________________                                        0          >95                 >95                                            1 hr.      69                  --                                             3.5 hrs.   47                  --                                             5.5 hrs.   38                  --                                             1 day      < 5                 74                                             3 days     < 5                 54                                             ______________________________________                                    

(8) Reaction of polyDMAEMA with AM.

200 parts of DMAEMA and 76.4 parts of acetic acid are dissolved in 1723parts of deionized water to give a solution with pH=6.5. Afterinitiating with 2 parts of 4,4'-azobis(4-cyanovaleric acid),polymerization is conducted at 60°, under nitrogen, for 1 hr. Residualmonomer is removed by dialysis, and polymer is then isolated bylyophilization.

121 parts of the lyophilized polymer, 38 parts of AM, and 1 part ofphenothiazine are then dissolved in 284 parts of a pH=7.8 phosphatebuffer. Upon incubation at 58°, 10% of the tertiary amine groups areconverted to quaternary ammonium groups within 6 hr.

(9) Emulsion polymerization of DMAEMA-acetate/acrylamide mixtures.General Method

The internal phase is an aqueous solution of the monomers. The externalphase is a paraffin oil such as Shellflex 131, Ashland Mineral Seal Oil,or Isopar M. Both the emulsifier and the initiator are oil soluble. Theadvantage of this method is that a 30% active product will flow readilyand has a viscosity in the range of 2000 to 2500 cps. An aqueoussolution of these high molecular weight polymers would be gelled above2% active concentration.

Prior to application the emulsion is inverted and dissolved in water togive a dilute solution. One part of a nonionic surfactant of theoxyethylated alkyl phenol type, such as Triton X-100 or Tergitol NP-33is dissolved in 979 parts of water. Then 20 parts of the inverseemulsion polymer is added. After the mixture has been stirred for 30minutes, the polymer has dissolved in water. The resulting solution is0.6% active and has a viscosity in the range of 2600 cps. (BrookfieldRVT at 5 rpm with #2 spindle.)

The principles of this invention are applied in the following examplesto produce cationic polyelectrolytes of variable quaternary ammoniumsalt content. Within each set of examples, only one physical parameteris changed--all other variables are held constant. Thus, in examples 9Aand 9B, quat content is varied by changing the AM to DMAEMAconcentration ratio (an example of combined kinetic and thermodynamiccontrol). In examples 9C through 9E, quat content is varied by changingthe pH of the reaction medium (an example of kinetic control alone). Inexamples 9C and 9F, quat content is varied by changing the temperatureof the reaction medium (an example of thermodynamic control alone).

EXAMPLE 9A Acrylamide/DMAEMA 1/1 Molar.

To a solution of 50 g of acetic acid in 410 grams of tap water is added131 grams of DMAEMA followed by 59.5 grams of acrylamide. The pH is 7.0without adjustment. This monomer solution is added slowly to a rapidlystirred solution of 30 grams of sorbitan monooleate (SMO) in 320 g ofShellflex 131. The resulting W/O emulsion is sparged with nitrogen,warmed to 50° C. and treated with a solution of 0.10 g of bisazoisobutyronitrile (Dupont VAZO) in 2 milliliters of benzene. Samplesare taken every 30 minutes. The first one actually immediately beforethe addition of the initiator. To a solution of 0.25 ml of TergitolNP-33 in 95 ml of water is added 5 ml of the sample emulsion. Themixture is stirred rapidly for 30 minutes and then treated with 2 g ofsodium chloride to reduce the viscosity of the solution. The reaction ismonitored by GLC. It is found that at the port temperature used,retroquaternization is complete, so that upon completion of thecopolymerization reaction, before equilibration, the acrylamidepercentage found can be used to calculate the approximate quat contentof the copolymer.

The gas-liquid chromatograph is equipped with a 6 foot by 0.25 inch allglass column. The liquid phase is 15% OV-3 and 0.1% Poly A-135. Thepolymer solutions are injected at a port temperature of 200° C. Thedetails are listed in the following table:

                  TABLE III                                                       ______________________________________                                        Time        Acrylamide      DMAEMA                                            Sample Hours    Wt%      Moles    Wt%    Moles                                ______________________________________                                        1      0        0.279    1.000    0.985  1.000                                2      1        0.218    0.779    0.760  0.771                                3      1.5      0.209    0.746    0.659  0.670                                4      2.5      0.162    0.578    0.410  0.417                                5      3        0.138    0.484    0.304  0.308                                6      4        0.121    0.433    0.163  0.165                                7      6        0.107    0.395    0.058  0.072                                8      6.5      0.099    0.355    0.046  0.057                                9      7        0.100    0.357    0.028  0.035                                ______________________________________                                    

As can be seen from the Table, after 7 hours g.l.c. shows only 3.5%residual DMAEMA but 35.7% acrylamide, indicating an approximate quatcontent of 35% (based on the DMAEMA in the copolymer). The percentagequaternization as determined by g.l.c. is generally in good agreementwith the values obtained on similar systems by Nmr analysis.

EXAMPLE 9B Acrylamide/DMAEMA 3/1 Molar pH 7.0

To a solution of 41.9 grams of glacial acetic acid in 350 grams of tapwater is added 109.6 grams of dimethylaminoethyl methacrylate (DMAEMA),followed by 148.7 grams of acrylamide (AM). The monomer solution pH is7.0. It is added slowly to a rapidly stirred solution of 30 grams ofsorbitan monooleate (SMO) in 320 grams of Shellflex 131. The resultingemulsion is sparged with nitrogen, warmed to 50° C. and treated with asolution 0.10 grams of bis azoisobutyronitrile (DuPont VAZO) in 2milliliters of benzene. The polymerization began after a 30 minuteinduction period. Samples are withdrawn every hour and the residualmonomer content determined by gas-liquid chromatography. After 5 hoursthe DMAEMA had completely disappeared and 20% of the acrylamide wasrecovered by GLC. This indicates that ≈60% of the DMAEMA has beenquaternized by the acrylamide. A small portion of the monomer solutionwas stored at 25° C. for 24 hours. The NMR spectrum showed that 50% ofthe DMAEMA had been quaternized.

EXAMPLE 9C Acrylamide/DMAEMA 2/1 Molar pH 7.7

To a solution of 40 grams of acetic acid in 350 grams of water is added131 grams of DMAEMA followed by 119 grams of acrylamide. The pH is 7.7.The rest of the procedure is the same or that followed in Example A.After 5 hours g.l.c. analysis showed no DMAEMA present while 49.5% ofthe acrylamide was recovered which indicates that ≈99% of the DMAEMA hadbeen quaternized. A small sample of the monomer solution was stored for24 hours at 25° C. The NMR spectrum showed that 73% of the DMAEMA hadbeen quaternized.

EXAMPLE 9D Acrylamide/DMAEMA 2/1 Molar pH 6.0

The procedure of Example B is repeated except that the pH of the monomersolution is adjusted to 6.0 with 12 grams of glacial acetic acid. Afterfive hours G.L.C. analysis showed there was no DMAEMA monomer remainingand only 8% of the acrylamide was recovered indicating that only ≈16% ofthe DMAEMA had been quaternized.

EXAMPLE 9E Acrylamide/DMAEMA 2/1 Molar pH 7.0

To a solution of 50.0 grams of acetic acid in 350 grams of water isadded 131 grams of DMAEMA followed by 119 grams of acrylamide. The pH ofthe solution is 7.0 without any adjustment. The rest of the procedure isthe same as followed in Example A. After 5 hours G.L.C. analysis showedthere was no DMAEMA monomer remaining, while 33% of the acrylamide wasrecovered. This indicates that ≈66% of the DMAEMA had been quaternized.

EXAMPLE 9F Acrylamide/DMAEMA 2/1 Molar pH 7.7

This example demonstrates the effect of reaction temperature on the quatcontent. Example 9C was repeated except that the temperature was raisedto 85° C. before the initiator was added. After 6 hours G.L.C. analysisshowed no DMAEMA and no acrylamide present. This indicates that none ofthe DMAEMA had been quaternized.

The products prepared (or reacted) in the above examples can berepresented by the following formulae.

1. DMAE-AM quaternary ammonium chloride is ##STR7##

2. DMAE-AN quaternary ammonium chloride is ##STR8##

3. DMAEMA-AM quaternary ammonium chloride is ##STR9##

4. Polymer of DMAEMA-AM quaternary ammonium chloride is ##STR10##

Polymer of DMAEMA with AM is ##STR11##

The above examples are presented by way of illustration and not oflimitation. Other modifications will be evident to those skilled in theart. For example, substituted acrylamides can also be employed forexample, those of the formula ##STR12## where R is hydrogen or asubstituted group, for example alkyl, and R' is a substituted group, forexample alkyl.

Other commercially available polymerizable tertiary amines can also beemployed for example: ##STR13## instead of DMAEMA.

In addition, the polymerizable compositions of this invention can becopolymerized with other polymerizable monomers such as those monomerscontaining polymerizable unsaturated groups.

USES

These compounds are useful in the clarification of water containing oilor suspended solids and especially oil coated solids. The applicationsinclude the resolution of oil field emulsions, oil in water emulsionsresulting from petroleum refinery processes, and emulsions of cuttingand rolling oils from metal working industries. The solids include silt,colloidal sulfur, organic polymers such as rubber and plastics, sewagesludge, and iron oxide from blast furnaces and steel manufacturingoperations.

The compounds may be used alone or in combination with other materialsincluding anionic polymers and inorganic coagulants such as alum, ferricchloride, zinc chloride, etc. They often allow a substantial reductionin the amount of the inorganic coagulants required for waterclarification, and sometimes even their complete elimination. Thereduction or elimination of the need for inorganic coagulants usuallyresults in a reduction in the volume of sludge and a consequent loweringof disposal costs.

These compounds may be used in simple settling tanks, or in centrifuges.They are particularly effective in air flotation cells.

FIELD EXAMPLES

The compositions of this invention are very effective in the resolutionof oil-in-water emulsions, as illustrated by the following examples.

Use Example A. At an oil field, compound 9B converted O/W petroleumemulsions to clear water at concentrations of 5-10 ppm (without the useof zinc chloride, which previously was required for good resolution).

Use Example B. At a refinery, the water effluent turbidity was reducedto 10-14 ppm of oil by the use of 0.06 to 0.10 ppm of compound 9C,together with 10 ppm of alum and 1 ppm of polyethylene polyamines. Thealum requirement was reduced from 19 ppm to 10 ppm.

The compositions of this invention are very effective in theclarification of water containing suspended solids, as illustrated bythe following examples.

Use Example C. At an oil refinery, raw river water was clarified forprocess use by treatment with 3 ppm Compound 9A, together with 25 ppm ofalum. The turbidity was reduced to 10 ppm.

Use Example D. At a steel plant, a waste stream containing mostly ironoxide was treated with 1 ppm of compound 9C and 0.25 ppm of a highmolecular weight anionic polymer. The turbidity was reduced to 1.5 FTU(formazine turbidity units) without the addition of ferric chloride orother inorganic coagulants.

Use Example E. At a polymer plant, effluent water from an A.P.I.separator, contaminated with organic solids was clarified by treatmentwith 0.375 ppm of Compound 9B.

The compositions of this invention are very effective in removing oiland oil coated solids from effluent waters when used in an air flotationcell such as a Wemco Depurator, as illustrated by the followingexamples.

Use Example F. At an oil field, the raw water contained 140 ppm oil.Without chemical treatment, the Wemco Depurator reduced the oil level to125 ppm. When 1.5 ppm of Compound 9C was added to the Wemco Depurator,the oil content was reduced to below 19 ppm.

Use Example G. At a petroleum refinery, the effluent water from anA.P.I. separator contained 150 ppm oil and solids and was unchanged bythe Wemco Depurator alone. Addition of 5 ppm of Compound 9C reduced theimpurities to 20 ppm.

Use Example H. At a petroleum refinery the oily effluent water wasimproved from 70 ppm to 20 ppm by treatment with 3 ppm of Compound 9C ina "Quadricell" air flotation cell.

Use Example I. At a petroleum refinery, treatment with Compound 9C in aWemco Depurator removed both oil and colloidal sulfur from the effluentwater.

It is understood that the above examples are for illustration purposesonly and modifications can be made without departing from the concept ofthe present invention.

We claim:
 1. A process of clarifying an aqueous system which is water containing oil, emulsified oil or suspended solids selected from the group consisting of oil coated solids, iron oxide containing solids, colloidal sulfur and organic polymers which comprises treating said system by adding thereto a clarifying amount of a polymer of a monomer which is a quaternary ammonium adduct of the formula ##STR14## where R is a polymerizable group terminating in ##STR15## moieties, the R' groups are alkyl groups, ##STR16## or CN, each R" is hydrogen or alkyl, X is an anion, and where the quaternary nitrogen is attached to four carbon atoms.
 2. A process of clarifying an aqueous system which comprises treating said system as in claim 1 wherein said polymer is a homopolymer.
 3. A process of clarifying an aqueous system which comprises treating said system as in claim 1 wherein said polymer is a copolymer.
 4. A process of clarifying an aqueous system which comprises treating said system as in claim 1 wherein in said polymer R is an alkylmethacryloxy or alkylmethacrylamide group, Z is ##STR17## and X is chloride or a carboxylate moiety.
 5. A process of clarifying an aqueous system which comprises treating said system as in claim 1 wherein in said polymer R is ##STR18##
 6. A process of clarifying an aqueous system which comprises treating said system with a terpolymer of the following units:(1) acrylamide (2) dimethylaminoethylmethacrylate, and (3) the quaternary adduct of dimethylaminoethylmethacrylate and acrylamide; and the anion is chloride or acetate. 